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Publié par | Read Books Ltd. |
Date de parution | 22 mars 2021 |
Nombre de lectures | 2 |
EAN13 | 9781528769167 |
Langue | English |
Poids de l'ouvrage | 5 Mo |
Informations légales : prix de location à la page 0,0500€. Cette information est donnée uniquement à titre indicatif conformément à la législation en vigueur.
Extrait
PRINCIPLES OF IRRIGATION ENGINEERING
ARID LANDS, WATER SUPPLY, STORAGE WORKS, DAMS, CANALS, WATER RIGHTS AND PRODUCTS
BY
FREDERICK HAYNES NEWELL
DIRECTOR U. S. RECLAMATION SERVICE .
AND
DANIEL WILLIAM MURPHY A. B., A. M., P H . D .
ENGINEER IN CHARGE OF DRAINAGE U. S. RECLAMATION SERVICE .
Copyright 2018 Read Books Ltd.
This book is copyright and may not be reproduced or copied in any way without the express permission of the publisher in writing
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
PREFACE
In the following pages an attempt is made to give an outline of the fundamental questions involved in undertaking and carrying out an irrigation enterprise. In presenting this matter in the form of a treatise on Irrigation Engineering, it is intended primarily for the use of students and engineers who desire to become acquainted with the general principles involved in considering the feasibility of, and in planning, constructing and operating irrigation systems. An attempt has also been made, however, to present the subject matter in such form that it may be read with profit by persons interested in irrigation, but without a thorough technical knowledge of the subject of hydraulics.
It is not possible in a book of ordinary length, to go into all of the details essential to successful irrigation construction and operation. The broader and more general aspects of the subject therefore are presented with the assumption, that where further details are necessary, it will be possible for the student to find them in one of the many technical books now available. The purpose of the work is therefore to assist the student and engineer by pointing out the essential questions to which special attention must be given.
In attempting to give this broad survey, the presentation has been made as simple and concise as possible. It is appreciated that even with engineers of large experience, there are certain broad principles, which though elementary, are worthy of frequent reconsideration. These principles when applied to new problems are frequently suggestive of different viewpoints and lead to a more thorough understanding of the work in hand. The designation, The Principles of Irrigation Engineering, has thus been selected as indicative of the attempted scope of the work.
Irrigation Engineering in its broadest aspects may be defined as the development of the water resources of the arid regions as relating to their conservation and use as a part of the wealth of the nation. More specifically, it deals with the methods of holding, controlling and distributing the waters needed in agriculture, and further, those matters which lead to financial success in the investments then made. As a science or branch of knowledge, it is the result of investigations worked out and information collected and systematized. It should furnish knowledge concerning the water supply and its use, especially as applied to human needs and happiness. It may be studied from the point of view of the statesman concerned with questions of public welfare, by the capitalist seeking an investment, and by the engineer, called upon to plan irrigation works.
CONTENTS
P REFACE
L IST OF P LATES
CHAPTER I
I RRIGATION
Definition - History and development - Needs and benefits - Methods of irrigation - Comparison of irrigated and non-irrigated lands.
CHAPTER II
I RRIGABLE L ANDS
Arid region - Topographic features - The soil - Preparation of lands - Location - Intensive farming - Climate.
CHAPTER III
W ATER S UPPLY
Source of water supply - Character of supply - Benefits of control - Study of water supply - Rainfall - Runoff - Influences affecting runoff - Character of watershed - Evaporation - Runoff on different watersheds - Comparison of runoff - Measurement of water - Units of measurement - Convenient equivalents - Methods of measurement - Results of stream measurement - Quality of water supply - Amount of water required for irrigation.
CHAPTER IV
D ESIGN AND C ONSTRUCTION OF C ANALS
Capacity - Location of canals - Alignment - Cross-section - Slopes and width of banks - Material for banks - Grades and velocities - Excavation - Specifications for excavation - Protection against seepage in canals - Lined canals - Roadways on banks - Lateral drainage - Right-of-way for canals.
CHAPTER V
C ANAL S TRUCTURES
Classification - Permanent and temporary structures - Headgates - Operating device - Turnouts - Checks and drops - Wasteways - Culverts - Flumes - Velocity and flow of water in flumes - Tunnels - Lining - Inverted siphons - Bridges - Measuring devices - Screens - Protection of canal structures.
CHAPTER VI
D ISTRIBUTION S YSTEMS
Canals and laterals - General plan of distribution system - Topographic surveys for lateral systems - Capacity of laterals - Location of laterals - Cross-secton of laterals - Points of delivery of water - Delivery box - Flumes and pipe distributaries - Accessibility to laterals.
CHAPTER VII
I RRIGATION BY P UMPING
General conditions - Source of supply - Character of pumps - Power for pumping - Wind-mills - Steam power - Gasoline and oil - Water power - Compressed air - Hydroelectric power - Cost of pumping - Feasibility of pumping.
CHAPTER VIII
D RAINAGE
Classification - Needs of drainage - Alkali and its effect - Benefit of drainage - Ground water - Effects of drainage on soils - Open and closed drains - Relief and intercepting drains - Drainage investigations - Capacity of drains - Depth of drains - Distance between drains - Grades and velocities of flow in drains.
CHAPTER IX
O PERATION AND M AINTENANCE
Distribution of water - Continuous flow - Periodic rotation - Length of irrigation season - Frequency of irrigation - Duty of water - Measurement of water used - Human element - Maintenance - Priming - Care of banks - Cleaning canals - Organization for operation and maintenance - Records - Costs.
CHAPTER X
S TORAGE W ORKS
Determination of storage supply - Annual runoff - Amount of runoff that can be stored - Seepage losses - Evaporation losses - Ratio of runoff to the storage capacity - Determination of storage required - Economic questions in storage - Cost of storage
CHAPTER XI
R ESERVOIR S ITES
General requirements - Survey of Reservoir sites - Contour maps - Computation of capacities - Choice of reservoir site - Shallow and deep reservoirs.
CHAPTER XII
D AM S ITES
General conditions - Surveys of dam sites - Foundation - Borings and test pits - Character of foundations - Character of materials for construction - Accessibility of materials for construction - Spillway - Records of stream flow - Kind of dam best adapted to suit conditions.
CHAPTER XIII
T IMBER D AMS
Kinds of dams - Early stages of development - Use of timber dams - Where timber dams are applicable - Conditions of Stability - Watertightness - Types of timber dams - Log and brush dams - Crib dams - Crib and pile dams - Framed dams - Limits of height.
CHAPTER XIV
E ARTH D AMS
Site for earth dams - Foundation - Selection of materials - Section of dam - Prevention of seepage under dam - Placing of materials in the dam - Placing of materials by hydraulic method - Compacting the material - Prevention of seepage through the dam - Core wall - Puddle core - Water-tight face - Cut-off trenches - Protection of slopes - Drainage of dam - Dikes - Limits of height of earth dams - Examples of earth dams.
CHAPTER XV
R OCK-FILL D AMS
Description - Advantages over earth dams - Site to which adapted - Foundation - Materials - Section and slopes - Water-tight section.
CHAPTER XVI
M ASONRY D AMS
Principles of Construction - Kinds of masonry dams - Rubble concrete - Foundations - Section - Concrete - Upward pressure - Curved dams - Multiple arch dams - Internal stresses - Safe limits for foundations - Overflow dams - Protection of lower toe from erosion - Safe heights - Typical masonry dams.
CHAPTER XVII
O UTLET W ORKS
Capacity - Location - Location of gates - Gate towers - Operation of gates - Erosion due to high velocities - Vibration of gates - Character of gates - Fishways - Spilling requirements - Spillway design - Determination of capacity - Location and type - Grades and velocities - Protection against erosion.
CHAPTER XVIII
W ATER R IGHTS
Definition - Origin of water rights in the United States - Riparian rights - Acquisition of water rights - Theory upon which granted - Beneficial use of water - Water rights apart from lands.
CHAPTER XIX
E CONOMIC F EATURES OF I RRIGATION
Feasibility of irrigation - Fundamental questions to be considered - Value of land - Increase in value - Soil, climate and crops - Permanence of water supply - Cost of constructing works - Other costs - Markets and transportation facilities - Security of investment - Ultimate results.
I NDEX
LIST OF PLATES
P LATE I
Fig. A.-Diverting dam in the Boise River, Idaho, a typical structure for taking out river water by gravity.
Fig. B.-Main northside canal of Minidoka Project, Idaho, illustrative of the larger irrigation canals, with power transmission lines located on the bank.
Fig. C.-Water being distributed to the fields through furrows after having been diverted from the river by gravity canals.
Fig. D.-Water being applied to the fields by flooding.
P LATE II
Fig. A.-A method of making a measurement of the amount of water in a stream, using current meter from bridge.
Fig. B.-Making s